This invention relates generally to an improved tube expander. More particularly, but not by way of limitation, this invention relates to an improved stop collar for a tube expander that prevents damage to the tube end during a rolling or expanding operation.
Examples of stop collar apparatus utilized in connection with tube expanders in the past, can be found in U.S. Pat. No. 3,426,565 issued to Donald E. Schott, Feb. 11, 1969 and in U.S. Pat. No. 3,924,433 issued Dec. 9, 1975 to Paul W. Martin.
In the 3,426,565 patent, there is illustrated a stop collar having a circular stop member located therein that is of the split-ring type. The 3,924,433 patent illustrates a stop collar that utilizes a plurality of finger-like members that extend into the interior of the stop collar to engage the end of the tube being expanded. Both of the stop members described are capable of functioning to prevent the entrance of the tube end into the tubing roller and, thus, are effective to prevent tube end damage.
A stop collar constructed in accordance with this invention, is an improvement over the stop collars and stop members described in the aforementioned patents. It is believed that this arrangement of stop collar and stop member is much simpler than that illustrated in the 3,924,433 patent and much stronger than that illustrated in the 3,425,565 patent. Yet, a stop collar constructed in accordance with the invention will be equally if not more effective in preventing damage to the tube end during the expanding operation.
Therefore, one object of this invention is to provide an improved stop collar that will prevent the entrance of the tube end into the tube expander and thereby prevent damage to the tube end during the expanding operation.